/**********
  This library is free software; you can redistribute it and/or modify it under
  the terms of the GNU Lesser General Public License as published by the
  Free Software Foundation; either version 2.1 of the License, or (at your
  option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)

  This library is distributed in the hope that it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
  more details.

  You should have received a copy of the GNU Lesser General Public License
  along with this library; if not, write to the Free Software Foundation, Inc.,
  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 **********/
// "liveMedia"
// Copyright (c) 1996-2009 Live Networks, Inc.  All rights reserved.
// RTCP
// Implementation

#include "RTCP.h"
#include "GroupsockHelper.h"
#include "rtcp_from_spec.h"
#include "Debug.h"

////////// RTCPMemberDatabase //////////

class RTCPMemberDatabase {
	public:
		RTCPMemberDatabase(RTCPInstance& ourRTCPInstance)
			: fOurRTCPInstance(ourRTCPInstance), fNumMembers(1 /*ourself*/),
			fTable(HashTable::create(ONE_WORD_HASH_KEYS)) {
			}

		virtual ~RTCPMemberDatabase() {
			delete fTable;
		}

		Boolean isMember(unsigned ssrc) const {
			return fTable->Lookup((char*)(long)ssrc) != NULL;
		}

		Boolean noteMembership(unsigned ssrc, unsigned curTimeCount) {
			Boolean isNew = !isMember(ssrc);

			if (isNew) {
				++fNumMembers;
			}

			// Record the current time, so we can age stale members
			fTable->Add((char*)(long)ssrc, (void*)(long)curTimeCount);

			return isNew;
		}

		Boolean remove(unsigned ssrc) {
			Boolean wasPresent = fTable->Remove((char*)(long)ssrc);
			if (wasPresent) {
				--fNumMembers;
			}
			return wasPresent;
		}

		unsigned numMembers() const {
			return fNumMembers;
		}

		void reapOldMembers(unsigned threshold);

	private:
		RTCPInstance& fOurRTCPInstance;
		unsigned fNumMembers;
		HashTable* fTable;
};

void RTCPMemberDatabase::reapOldMembers(unsigned threshold) {
	Boolean foundOldMember;
	unsigned oldSSRC = 0;

	do {
		foundOldMember = False;

		HashTable::Iterator* iter
			= HashTable::Iterator::create(*fTable);
		unsigned long timeCount;
		char const* key;
		while ((timeCount = (unsigned long)(iter->next(key))) != 0) {
		Debug(ckite_log_message, "RTCPMemberDatabase::reapOldMembers ssrc = %lx\n", (unsigned long)key);
#ifdef DEBUG
			Debug(ckite_log_message, "reap: checking SSRC 0x%lx: %ld (threshold %d)\n", (unsigned long)key, timeCount, threshold);
#endif
			if (timeCount < (unsigned long)threshold) { // this SSRC is old
				unsigned long ssrc = (unsigned long)key;
				oldSSRC = (unsigned)ssrc;
				foundOldMember = True;
			}
		}
		delete iter;

		if (foundOldMember) {
		Debug(ckite_log_message, "RTCPMemberDatabase::reapOldMembers oldssrc = %x\n", oldSSRC);
#ifdef DEBUG
			Debug(ckite_log_message, "reap: removing SSRC 0x%x\n", oldSSRC);
#endif
			fOurRTCPInstance.removeSSRC(oldSSRC, True);
		}
	} while (foundOldMember);
}


////////// RTCPInstance //////////

static double dTimeNow() {
	struct timeval timeNow;
	gettimeofday(&timeNow, NULL);
	return (double) (timeNow.tv_sec + timeNow.tv_usec/1000000.0);
}

static unsigned const maxPacketSize = 1450;
// bytes (1500, minus some allowance for IP, UDP, UMTP headers)
static unsigned const preferredPacketSize = 1000; // bytes

RTCPInstance::RTCPInstance(UsageEnvironment& env, Groupsock* RTCPgs,
		unsigned totSessionBW,
		unsigned char const* cname,
		RTPSink* sink, RTPSource const* source,
		Boolean isSSMSource)
: Medium(env), fRTCPInterface(this, RTCPgs), fTotSessionBW(totSessionBW),
	fSink(sink), fSource(source), fIsSSMSource(isSSMSource),
	fCNAME(RTCP_SDES_CNAME, cname), fOutgoingReportCount(1),
	fAveRTCPSize(0), fIsInitial(1), fPrevNumMembers(0),
	fLastSentSize(0), fLastReceivedSize(0), fLastReceivedSSRC(0),
	fTypeOfEvent(EVENT_UNKNOWN), fTypeOfPacket(PACKET_UNKNOWN_TYPE),
	fHaveJustSentPacket(False), fLastPacketSentSize(0),
	fByeHandlerTask(NULL), fByeHandlerClientData(NULL),
	fSRHandlerTask(NULL), fSRHandlerClientData(NULL),
	fRRHandlerTask(NULL), fRRHandlerClientData(NULL),
	fSpecificRRHandlerTable(NULL) {
#ifdef DEBUG
		Debug(ckite_log_message, "RTCPInstance[%p]::RTCPInstance()\n", this);
#endif
		if (fTotSessionBW == 0) { // not allowed!
			env << "RTCPInstance::RTCPInstance error: totSessionBW parameter should not be zero!\n";
			fTotSessionBW = 1;
		}

		if (isSSMSource) RTCPgs->multicastSendOnly(); // don't receive multicast

		double timeNow = dTimeNow();
		fPrevReportTime = fNextReportTime = timeNow;

		fKnownMembers = new RTCPMemberDatabase(*this);
		fInBuf = new unsigned char[maxPacketSize];
		if (fKnownMembers == NULL || fInBuf == NULL) return;

		// A hack to save buffer space, because RTCP packets are always small:
		unsigned savedMaxSize = OutPacketBuffer::maxSize;
		OutPacketBuffer::maxSize = maxPacketSize;
		fOutBuf = new OutPacketBuffer(preferredPacketSize, maxPacketSize);
		OutPacketBuffer::maxSize = savedMaxSize;
		if (fOutBuf == NULL) return;

		// Arrange to handle incoming reports from others:
		TaskScheduler::BackgroundHandlerProc* handler
			= (TaskScheduler::BackgroundHandlerProc*)&incomingReportHandler;
		fRTCPInterface.startNetworkReading(handler);

		// Send our first report.
		fTypeOfEvent = EVENT_REPORT;
		onExpire(this);
	}

struct RRHandlerRecord {
	TaskFunc* rrHandlerTask;
	void* rrHandlerClientData;
};

RTCPInstance::~RTCPInstance() {
#ifdef DEBUG
	Debug(ckite_log_message, "RTCPInstance[%p]::~RTCPInstance()\n", this);
#endif
	// Turn off background read handling:
	fRTCPInterface.stopNetworkReading();

	// Begin by sending a BYE.  We have to do this immediately, without
	// 'reconsideration', because "this" is going away.
	fTypeOfEvent = EVENT_BYE; // not used, but...
	sendBYE();

	if (fSpecificRRHandlerTable != NULL) {
		AddressPortLookupTable::Iterator iter(*fSpecificRRHandlerTable);
		RRHandlerRecord* rrHandler;
		while ((rrHandler = (RRHandlerRecord*)iter.next()) != NULL) {
			delete rrHandler;
		}
		delete fSpecificRRHandlerTable;
	}

	delete fKnownMembers;
	delete fOutBuf;
	delete[] fInBuf;
}

RTCPInstance* RTCPInstance::createNew(UsageEnvironment& env, Groupsock* RTCPgs,
		unsigned totSessionBW,
		unsigned char const* cname,
		RTPSink* sink, RTPSource const* source,
		Boolean isSSMSource) {
	return new RTCPInstance(env, RTCPgs, totSessionBW, cname, sink, source,
			isSSMSource);
}

Boolean RTCPInstance::lookupByName(UsageEnvironment& env,
		char const* instanceName,
		RTCPInstance*& resultInstance) {
	resultInstance = NULL; // unless we succeed

	Medium* medium;
	if (!Medium::lookupByName(env, instanceName, medium)) return False;

	if (!medium->isRTCPInstance()) {
		env.setResultMsg(instanceName, " is not a RTCP instance");
		return False;
	}

	resultInstance = (RTCPInstance*)medium;
	return True;
}

Boolean RTCPInstance::isRTCPInstance() const {
	return True;
}

unsigned RTCPInstance::numMembers() const {
	if (fKnownMembers == NULL) return 0;

	return fKnownMembers->numMembers();
}

void RTCPInstance::setByeHandler(TaskFunc* handlerTask, void* clientData,
		Boolean handleActiveParticipantsOnly) {
	fByeHandlerTask = handlerTask;
	fByeHandlerClientData = clientData;
	fByeHandleActiveParticipantsOnly = handleActiveParticipantsOnly;
}

void RTCPInstance::setSRHandler(TaskFunc* handlerTask, void* clientData) {
	fSRHandlerTask = handlerTask;
	fSRHandlerClientData = clientData;
}

void RTCPInstance::setRRHandler(TaskFunc* handlerTask, void* clientData) {
	fRRHandlerTask = handlerTask;
	fRRHandlerClientData = clientData;
}

void RTCPInstance
::setSpecificRRHandler(netAddressBits fromAddress, Port fromPort,
		TaskFunc* handlerTask, void* clientData) {
	if (handlerTask == NULL && clientData == NULL) {
		unsetSpecificRRHandler(fromAddress, fromPort);
		return;
	}

	RRHandlerRecord* rrHandler = new RRHandlerRecord;
	rrHandler->rrHandlerTask = handlerTask;
	rrHandler->rrHandlerClientData = clientData;
	if (fSpecificRRHandlerTable == NULL) {
		fSpecificRRHandlerTable = new AddressPortLookupTable;
	}
	fSpecificRRHandlerTable->Add(fromAddress, (~0), fromPort, rrHandler);
}

void RTCPInstance
::unsetSpecificRRHandler(netAddressBits fromAddress, Port fromPort) {
	if (fSpecificRRHandlerTable == NULL) return;

	RRHandlerRecord* rrHandler
		= (RRHandlerRecord*)(fSpecificRRHandlerTable->Lookup(fromAddress, (~0), fromPort));
	if (rrHandler != NULL) {
		fSpecificRRHandlerTable->Remove(fromAddress, (~0), fromPort);
		delete rrHandler;
	}
}

void RTCPInstance::setStreamSocket(int sockNum,
		unsigned char streamChannelId) {
	// Turn off background read handling:
	fRTCPInterface.stopNetworkReading();

	// Switch to RTCP-over-TCP:
	fRTCPInterface.setStreamSocket(sockNum, streamChannelId);

	// Turn background reading back on:
	TaskScheduler::BackgroundHandlerProc* handler
		= (TaskScheduler::BackgroundHandlerProc*)&incomingReportHandler;
	fRTCPInterface.startNetworkReading(handler);
}

void RTCPInstance::addStreamSocket(int sockNum,
		unsigned char streamChannelId) {

	  if (fRTCPInterface.fTCPStreams != NULL)
	  	 return; // add by wayde

	// First, turn off background read handling for the default (UDP) socket:
	fRTCPInterface.stopNetworkReading();

	// Add the RTCP-over-TCP interface:
	fRTCPInterface.setStreamSocket(sockNum, streamChannelId);

	// Turn on background reading for this socket (in case it's not on already):
	TaskScheduler::BackgroundHandlerProc* handler
		= (TaskScheduler::BackgroundHandlerProc*)&incomingReportHandler;
	fRTCPInterface.startNetworkReading(handler);
}

static unsigned const IP_UDP_HDR_SIZE = 28;
// overhead (bytes) of IP and UDP hdrs

#define ADVANCE(n) pkt += (n); packetSize -= (n)

void RTCPInstance::incomingReportHandler(RTCPInstance* instance,
		int /*mask*/) {
	instance->incomingReportHandler1();
}

void RTCPInstance::incomingReportHandler1() {
	unsigned char* pkt = fInBuf;
	unsigned packetSize;
	struct sockaddr_in fromAddress;
	int typeOfPacket = PACKET_UNKNOWN_TYPE;

	Debug(ckite_log_message, "RTCPInstance::incomingReportHandle1\n");

	do {
		int tcpReadStreamSocketNum = fRTCPInterface.nextTCPReadStreamSocketNum();
		unsigned char tcpReadStreamChannelId = fRTCPInterface.nextTCPReadStreamChannelId();
		if (!fRTCPInterface.handleRead(pkt, maxPacketSize,
					packetSize, fromAddress)) {
			break;
		}

		// Ignore the packet if it was looped-back from ourself:
		if (RTCPgs()->wasLoopedBackFromUs(envir(), fromAddress)) {
			// However, we still want to handle incoming RTCP packets from
			// *other processes* on the same machine.  To distinguish this
			// case from a true loop-back, check whether we've just sent a
			// packet of the same size.  (This check isn't perfect, but it seems
			// to be the best we can do.)
			if (fHaveJustSentPacket && fLastPacketSentSize == packetSize) {
				// This is a true loop-back:
				fHaveJustSentPacket = False;
				break; // ignore this packet
			}
		}

		if (fIsSSMSource) {
			// This packet was received via unicast.  'Reflect' it by resending
			// it to the multicast group.
			// NOTE: Denial-of-service attacks are possible here.
			// Users of this software may wish to add their own,
			// application-specific mechanism for 'authenticating' the
			// validity of this packet before reflecting it.
			fRTCPInterface.sendPacket(pkt, packetSize);
			fHaveJustSentPacket = True;
			fLastPacketSentSize = packetSize;
		}

#ifdef DEBUG
		Debug(ckite_log_message, "[%p]saw incoming RTCP packet (from address %s, port %d)\n", this, our_inet_ntoa(fromAddress.sin_addr), ntohs(fromAddress.sin_port));
		unsigned char* p = pkt;
		for (unsigned i = 0; i < packetSize; ++i) {
			if (i%4 == 0) Debug(ckite_log_message, " ");
			Debug(ckite_log_message, "%02x", p[i]);
		}
		Debug(ckite_log_message, "\n");
#endif
		int totPacketSize = IP_UDP_HDR_SIZE + packetSize;

		// Check the RTCP packet for validity:
		// It must at least contain a header (4 bytes), and this header
		// must be version=2, with no padding bit, and a payload type of
		// SR (200) or RR (201):
		if (packetSize < 4) break;
		unsigned rtcpHdr = ntohl(*(unsigned*)pkt);
		if ((rtcpHdr & 0xE0FE0000) != (0x80000000 | (RTCP_PT_SR<<16))) {
#ifdef DEBUG
			Debug(ckite_log_message, "rejected bad RTCP packet: header 0x%08x\n", rtcpHdr);
#endif
			break;
		}

		// Process each of the individual RTCP 'subpackets' in (what may be)
		// a compound RTCP packet.
		unsigned reportSenderSSRC = 0;
		Boolean packetOK = False;
		while (1) {
			unsigned rc = (rtcpHdr>>24)&0x1F;
			unsigned pt = (rtcpHdr>>16)&0xFF;
			unsigned length = 4*(rtcpHdr&0xFFFF); // doesn't count hdr
			ADVANCE(4); // skip over the header
			if (length > packetSize) break;

			// Assume that each RTCP subpacket begins with a 4-byte SSRC:
			if (length < 4) break; length -= 4;
			reportSenderSSRC = ntohl(*(unsigned*)pkt); ADVANCE(4);
			Debug(ckite_log_message, "RTCPInstance::incomingReportHandler1 ssrc = %x\n", reportSenderSSRC);

			Boolean subPacketOK = False;
			switch (pt) {
			case RTCP_PT_SR: {
#if 1//def DEBUG
								 Debug(ckite_log_message, "SR\n");
#endif
								 if (length < 20) break; length -= 20;

								 // Extract the NTP timestamp, and note this:
								 unsigned NTPmsw = ntohl(*(unsigned*)pkt); ADVANCE(4);
								 unsigned NTPlsw = ntohl(*(unsigned*)pkt); ADVANCE(4);
								 unsigned rtpTimestamp = ntohl(*(unsigned*)pkt); ADVANCE(4);
								 if (fSource != NULL) {
									 RTPReceptionStatsDB& receptionStats
										 = fSource->receptionStatsDB();
									 receptionStats.noteIncomingSR(reportSenderSSRC,
											 NTPmsw, NTPlsw, rtpTimestamp);
								 }
								 ADVANCE(8); // skip over packet count, octet count

								 // If a 'SR handler' was set, call it now:
								 if (fSRHandlerTask != NULL) (*fSRHandlerTask)(fSRHandlerClientData);

								 // The rest of the SR is handled like a RR (so, no "break;" here)
							 }
			case RTCP_PT_RR: {
#if 1//def DEBUG
								 Debug(ckite_log_message, "RR\n");
#endif
								 unsigned reportBlocksSize = rc*(6*4);
								 if (length < reportBlocksSize) break;
								 length -= reportBlocksSize;

								 if (fSink != NULL) {
									 // Use this information to update stats about our transmissions:
									 RTPTransmissionStatsDB& transmissionStats = fSink->transmissionStatsDB();
									 for (unsigned i = 0; i < rc; ++i) {
										 unsigned senderSSRC = ntohl(*(unsigned*)pkt); ADVANCE(4);
										 // We care only about reports about our own transmission, not others'
										 if (senderSSRC == fSink->SSRC()) {
											 unsigned lossStats = ntohl(*(unsigned*)pkt); ADVANCE(4);
											 unsigned highestReceived = ntohl(*(unsigned*)pkt); ADVANCE(4);
											 unsigned jitter = ntohl(*(unsigned*)pkt); ADVANCE(4);
											 unsigned timeLastSR = ntohl(*(unsigned*)pkt); ADVANCE(4);
											 unsigned timeSinceLastSR = ntohl(*(unsigned*)pkt); ADVANCE(4);
											 transmissionStats.noteIncomingRR(reportSenderSSRC, fromAddress,
													 lossStats,
													 highestReceived, jitter,
													 timeLastSR, timeSinceLastSR);
										 } else {
											 ADVANCE(4*5);
										 }
									 }
								 } else {
									 ADVANCE(reportBlocksSize);
								 }

								 if (pt == RTCP_PT_RR) { // i.e., we didn't fall through from 'SR'
									 // If a 'RR handler' was set, call it now:
									 // Specific RR handler:
									 Debug(ckite_log_message, "RTCPInstance pt == RTCP_PT_RR\n");
									 Debug(ckite_log_message, "fSpecificRRHandlerTable = %p\n", fSpecificRRHandlerTable);
									 if (fSpecificRRHandlerTable != NULL) {
										 netAddressBits fromAddr;
										 portNumBits fromPortNum;
										 if (tcpReadStreamSocketNum < 0) {
											 // Normal case: We read the RTCP packet over UDP
											 fromAddr = fromAddress.sin_addr.s_addr;
											 fromPortNum = ntohs(fromAddress.sin_port);
										 } else {
											 // Special case: We read the RTCP packet over TCP (interleaved)
											 // Hack: Use the TCP socket and channel id to look up the handler
											 fromAddr = tcpReadStreamSocketNum;
											 fromPortNum = tcpReadStreamChannelId;
										 }
										 Port fromPort(fromPortNum);
										 RRHandlerRecord* rrHandler
											 = (RRHandlerRecord*)(fSpecificRRHandlerTable->Lookup(fromAddr, (~0), fromPort));
										 if (rrHandler != NULL) {
											 if (rrHandler->rrHandlerTask != NULL) {
												 Debug(ckite_log_message, "RTCPInstance  rrHandleTask callback\n");
												 (*(rrHandler->rrHandlerTask))(rrHandler->rrHandlerClientData);
											 }
										 }
									 }

									 // General RR handler:
									 if (fRRHandlerTask != NULL) (*fRRHandlerTask)(fRRHandlerClientData);
								 }

								 subPacketOK = True;
								 typeOfPacket = PACKET_RTCP_REPORT;
								 break;
							 }
			case RTCP_PT_BYE: {
#if 1//def DEBUG
								  Debug(ckite_log_message, "BYE\n");
#endif
								  // If a 'BYE handler' was set, call it now:
								  TaskFunc* byeHandler = fByeHandlerTask;
								  if (byeHandler != NULL
										  && (!fByeHandleActiveParticipantsOnly
											  || (fSource != NULL
												  && fSource->receptionStatsDB().lookup(reportSenderSSRC) != NULL)
											  || (fSink != NULL
												  && fSink->transmissionStatsDB().lookup(reportSenderSSRC) != NULL))) {
									  fByeHandlerTask = NULL;
									  // we call this only once by default
									  (*byeHandler)(fByeHandlerClientData);
								  }

								  // We should really check for & handle >1 SSRCs being present #####

								  subPacketOK = True;
								  typeOfPacket = PACKET_BYE;
								  break;
							  }
							  // Later handle SDES, APP, and compound RTCP packets #####
			default:
#ifdef DEBUG
							  Debug(ckite_log_message, "UNSUPPORTED TYPE(0x%x)\n", pt);
#endif
							  subPacketOK = True;
							  break;
			}
			if (!subPacketOK) break;

			// need to check for (& handle) SSRC collision! #####

#ifdef DEBUG
			Debug(ckite_log_message, "validated RTCP subpacket (type %d): %d, %d, %d, 0x%08x\n", typeOfPacket, rc, pt, length, reportSenderSSRC);
#endif

			// Skip over any remaining bytes in this subpacket:
			ADVANCE(length);

			// Check whether another RTCP 'subpacket' follows:
			if (packetSize == 0) {
				packetOK = True;
				break;
			} else if (packetSize < 4) {
#ifdef DEBUG
				Debug(ckite_log_message, "extraneous %d bytes at end of RTCP packet!\n", packetSize);
#endif
				break;
			}
			rtcpHdr = ntohl(*(unsigned*)pkt);
			if ((rtcpHdr & 0xC0000000) != 0x80000000) {
#ifdef DEBUG
				Debug(ckite_log_message, "bad RTCP subpacket: header 0x%08x\n", rtcpHdr);
#endif
				break;
			}
		}

		if (!packetOK) {
#ifdef DEBUG
			Debug(ckite_log_message, "rejected bad RTCP subpacket: header 0x%08x\n", rtcpHdr);
#endif
			break;
		} else {
#ifdef DEBUG
			Debug(ckite_log_message, "validated entire RTCP packet\n");
#endif
		}

		onReceive(typeOfPacket, totPacketSize, reportSenderSSRC);
	} while (0);
}

void RTCPInstance::onReceive(int typeOfPacket, int totPacketSize,
		unsigned ssrc) {
	fTypeOfPacket = typeOfPacket;
	fLastReceivedSize = totPacketSize;
	fLastReceivedSSRC = ssrc;

	int members = (int)numMembers();
	int senders = (fSink != NULL) ? 1 : 0;

	OnReceive(this, // p
			this, // e
			&members, // members
			&fPrevNumMembers, // pmembers
			&senders, // senders
			&fAveRTCPSize, // avg_rtcp_size
			&fPrevReportTime, // tp
			dTimeNow(), // tc
			fNextReportTime);
}

void RTCPInstance::sendReport() {
	// Hack: Don't send a SR during those (brief) times when the timestamp of the
	// next outgoing RTP packet has been preset, to ensure that that timestamp gets
	// used for that outgoing packet. (David Bertrand, 2006.07.18)
	if (fSink != NULL && fSink->nextTimestampHasBeenPreset()) return;

#ifdef DEBUG
	Debug(ckite_log_message, "sending REPORT\n");
#endif
	// Begin by including a SR and/or RR report:
	addReport();

	// Then, include a SDES:
	addSDES();

	// Send the report:
	sendBuiltPacket();

	// Periodically clean out old members from our SSRC membership database:
	const unsigned membershipReapPeriod = 5;
	if ((++fOutgoingReportCount) % membershipReapPeriod == 0) {
		unsigned threshold = fOutgoingReportCount - membershipReapPeriod;
		fKnownMembers->reapOldMembers(threshold);
	}
}

void RTCPInstance::sendBYE() {
#ifdef DEBUG
	Debug(ckite_log_message, "sending BYE\n");
#endif
	// The packet must begin with a SR and/or RR report:
	addReport();

	addBYE();
	sendBuiltPacket();
}

void RTCPInstance::sendBuiltPacket() {
#ifdef DEBUG
	Debug(ckite_log_message, "sending RTCP packet\n");
	unsigned char* p = fOutBuf->packet();
	for (unsigned i = 0; i < fOutBuf->curPacketSize(); ++i) {
		if (i%4 == 0) Debug(ckite_log_message," ");
		Debug(ckite_log_message, "%02x", p[i]);
	}
	Debug(ckite_log_message, "\n");
#endif
	unsigned reportSize = fOutBuf->curPacketSize();
	fRTCPInterface.sendPacket(fOutBuf->packet(), reportSize);
	fOutBuf->resetOffset();

	fLastSentSize = IP_UDP_HDR_SIZE + reportSize;
	fHaveJustSentPacket = True;
	fLastPacketSentSize = reportSize;
}

int RTCPInstance::checkNewSSRC() {
	return fKnownMembers->noteMembership(fLastReceivedSSRC,
			fOutgoingReportCount);
}

void RTCPInstance::removeLastReceivedSSRC() {
	removeSSRC(fLastReceivedSSRC, False/*keep stats around*/);
}

void RTCPInstance::removeSSRC(u_int32_t ssrc, Boolean alsoRemoveStats) {
	fKnownMembers->remove(ssrc);

	if (alsoRemoveStats) {
		// Also, remove records of this SSRC from any reception or transmission stats
		if (fSource != NULL) fSource->receptionStatsDB().removeRecord(ssrc);
		if (fSink != NULL) fSink->transmissionStatsDB().removeRecord(ssrc);
	}
}

void RTCPInstance::onExpire(RTCPInstance* instance) {
	instance->onExpire1();
}

// Member functions to build specific kinds of report:

void RTCPInstance::addReport() {
	// Include a SR or a RR, depending on whether we
	// have an associated sink or source:
	if (fSink != NULL) {
		addSR();
	} else if (fSource != NULL) {
		addRR();
	}
}

void RTCPInstance::addSR() {
	// ASSERT: fSink != NULL

	enqueueCommonReportPrefix(RTCP_PT_SR, fSink->SSRC(),
			5 /* extra words in a SR */);

	// Now, add the 'sender info' for our sink

	// Insert the NTP and RTP timestamps for the 'wallclock time':
	struct timeval timeNow;
	gettimeofday(&timeNow, NULL);
	fOutBuf->enqueueWord(timeNow.tv_sec + 0x83AA7E80);
	// NTP timestamp most-significant word (1970 epoch -> 1900 epoch)
	double fractionalPart = (timeNow.tv_usec/15625.0)*0x04000000; // 2^32/10^6
	fOutBuf->enqueueWord((unsigned)(fractionalPart+0.5));
	// NTP timestamp least-significant word
	unsigned rtpTimestamp = fSink->convertToRTPTimestamp(timeNow);
	fOutBuf->enqueueWord(rtpTimestamp); // RTP ts

	// Insert the packet and byte counts:
	fOutBuf->enqueueWord(fSink->packetCount());
	fOutBuf->enqueueWord(fSink->octetCount());

	enqueueCommonReportSuffix();
}

void RTCPInstance::addRR() {
	// ASSERT: fSource != NULL

	enqueueCommonReportPrefix(RTCP_PT_RR, fSource->SSRC());
	enqueueCommonReportSuffix();
}

void RTCPInstance::enqueueCommonReportPrefix(unsigned char packetType,
		unsigned SSRC,
		unsigned numExtraWords) {
	unsigned numReportingSources;
	if (fSource == NULL) {
		numReportingSources = 0; // we don't receive anything
	} else {
		RTPReceptionStatsDB& allReceptionStats
			= fSource->receptionStatsDB();
		numReportingSources = allReceptionStats.numActiveSourcesSinceLastReset();
		// This must be <32, to fit in 5 bits:
		if (numReportingSources >= 32) { numReportingSources = 32; }
		// Later: support adding more reports to handle >32 sources (unlikely)#####
	}

	unsigned rtcpHdr = 0x80000000; // version 2, no padding
	rtcpHdr |= (numReportingSources<<24);
	rtcpHdr |= (packetType<<16);
	rtcpHdr |= (1 + numExtraWords + 6*numReportingSources);
	// each report block is 6 32-bit words long
	fOutBuf->enqueueWord(rtcpHdr);

	fOutBuf->enqueueWord(SSRC);
}

void RTCPInstance::enqueueCommonReportSuffix() {
	// Output the report blocks for each source:
	if (fSource != NULL) {
		RTPReceptionStatsDB& allReceptionStats
			= fSource->receptionStatsDB();

		RTPReceptionStatsDB::Iterator iterator(allReceptionStats);
		while (1) {
			RTPReceptionStats* receptionStats = iterator.next();
			if (receptionStats == NULL) break;
			enqueueReportBlock(receptionStats);
		}

		allReceptionStats.reset(); // because we have just generated a report
	}
}

void
RTCPInstance::enqueueReportBlock(RTPReceptionStats* stats) {
	fOutBuf->enqueueWord(stats->SSRC());

	unsigned highestExtSeqNumReceived = stats->highestExtSeqNumReceived();

	unsigned totNumExpected
		= highestExtSeqNumReceived - stats->baseExtSeqNumReceived();
	int totNumLost = totNumExpected - stats->totNumPacketsReceived();
	// 'Clamp' this loss number to a 24-bit signed value:
	if (totNumLost > 0x007FFFFF) {
		totNumLost = 0x007FFFFF;
	} else if (totNumLost < 0) {
		if (totNumLost < -0x00800000) totNumLost = 0x00800000; // unlikely, but...
		totNumLost &= 0x00FFFFFF;
	}

	unsigned numExpectedSinceLastReset
		= highestExtSeqNumReceived - stats->lastResetExtSeqNumReceived();
	int numLostSinceLastReset
		= numExpectedSinceLastReset - stats->numPacketsReceivedSinceLastReset();
	unsigned char lossFraction;
	if (numExpectedSinceLastReset == 0 || numLostSinceLastReset < 0) {
		lossFraction = 0;
	} else {
		lossFraction = (unsigned char)
			((numLostSinceLastReset << 8) / numExpectedSinceLastReset);
	}

	fOutBuf->enqueueWord((lossFraction<<24) | totNumLost);
	fOutBuf->enqueueWord(highestExtSeqNumReceived);

	fOutBuf->enqueueWord(stats->jitter());

	unsigned NTPmsw = stats->lastReceivedSR_NTPmsw();
	unsigned NTPlsw = stats->lastReceivedSR_NTPlsw();
	unsigned LSR = ((NTPmsw&0xFFFF)<<16)|(NTPlsw>>16); // middle 32 bits
	fOutBuf->enqueueWord(LSR);

	// Figure out how long has elapsed since the last SR rcvd from this src:
	struct timeval const& LSRtime = stats->lastReceivedSR_time(); // "last SR"
	struct timeval timeNow, timeSinceLSR;
	gettimeofday(&timeNow, NULL);
	if (timeNow.tv_usec < LSRtime.tv_usec) {
		timeNow.tv_usec += 1000000;
		timeNow.tv_sec -= 1;
	}
	timeSinceLSR.tv_sec = timeNow.tv_sec - LSRtime.tv_sec;
	timeSinceLSR.tv_usec = timeNow.tv_usec - LSRtime.tv_usec;
	// The enqueued time is in units of 1/65536 seconds.
	// (Note that 65536/1000000 == 1024/15625)
	unsigned DLSR;
	if (LSR == 0) {
		DLSR = 0;
	} else {
		DLSR = (timeSinceLSR.tv_sec<<16)
			| ( (((timeSinceLSR.tv_usec<<11)+15625)/31250) & 0xFFFF);
	}
	fOutBuf->enqueueWord(DLSR);
}

void RTCPInstance::addSDES() {
	// For now we support only the CNAME item; later support more #####

	// Begin by figuring out the size of the entire SDES report:
	unsigned numBytes = 4;
	// counts the SSRC, but not the header; it'll get subtracted out
	numBytes += fCNAME.totalSize(); // includes id and length
	numBytes += 1; // the special END item

	unsigned num4ByteWords = (numBytes + 3)/4;

	unsigned rtcpHdr = 0x81000000; // version 2, no padding, 1 SSRC chunk
	rtcpHdr |= (RTCP_PT_SDES<<16);
	rtcpHdr |= num4ByteWords;
	fOutBuf->enqueueWord(rtcpHdr);

	if (fSource != NULL) {
		fOutBuf->enqueueWord(fSource->SSRC());
	} else if (fSink != NULL) {
		fOutBuf->enqueueWord(fSink->SSRC());
	}

	// Add the CNAME:
	fOutBuf->enqueue(fCNAME.data(), fCNAME.totalSize());

	// Add the 'END' item (i.e., a zero byte), plus any more needed to pad:
	unsigned numPaddingBytesNeeded = 4 - (fOutBuf->curPacketSize() % 4);
	unsigned char const zero = '\0';
	while (numPaddingBytesNeeded-- > 0) fOutBuf->enqueue(&zero, 1);
}

void RTCPInstance::addBYE() {
	unsigned rtcpHdr = 0x81000000; // version 2, no padding, 1 SSRC
	rtcpHdr |= (RTCP_PT_BYE<<16);
	rtcpHdr |= 1; // 2 32-bit words total (i.e., with 1 SSRC)
	fOutBuf->enqueueWord(rtcpHdr);

	if (fSource != NULL) {
		fOutBuf->enqueueWord(fSource->SSRC());
	} else if (fSink != NULL) {
		fOutBuf->enqueueWord(fSink->SSRC());
	}
}

void RTCPInstance::schedule(double nextTime) {
	fNextReportTime = nextTime;

	double secondsToDelay = nextTime - dTimeNow();
#ifdef DEBUG
	Debug(ckite_log_message, "schedule(%f->%f)\n", secondsToDelay, nextTime);
#endif
	int usToGo = (int)(secondsToDelay * 1000000);
	nextTask() = envir().taskScheduler().scheduleDelayedTask(usToGo,
			(TaskFunc*)RTCPInstance::onExpire, this);
}

void RTCPInstance::reschedule(double nextTime) {
	envir().taskScheduler().unscheduleDelayedTask(nextTask());
	schedule(nextTime);
}

void RTCPInstance::onExpire1() {
	// Note: fTotSessionBW is kbits per second
	double rtcpBW = 0.05*fTotSessionBW*1024/8; // -> bytes per second

	OnExpire(this, // event
			numMembers(), // members
			(fSink != NULL) ? 1 : 0, // senders
			rtcpBW, // rtcp_bw
			(fSink != NULL) ? 1 : 0, // we_sent
			&fAveRTCPSize, // ave_rtcp_size
			&fIsInitial, // initial
			dTimeNow(), // tc
			&fPrevReportTime, // tp
			&fPrevNumMembers // pmembers
			);
}

////////// SDESItem //////////

SDESItem::SDESItem(unsigned char tag, unsigned char const* value) {
	unsigned length = strlen((char const*)value);
	if (length > 511) length = 511;

	fData[0] = tag;
	fData[1] = (unsigned char)length;
	memmove(&fData[2], value, length);

	// Pad the trailing bytes to a 4-byte boundary:
	while ((length)%4 > 0) fData[2 + length++] = '\0';
}

unsigned SDESItem::totalSize() const {
	return 2 + (unsigned)fData[1];
}


////////// Implementation of routines imported by the "rtcp_from_spec" C code

extern "C" void Schedule(double nextTime, event e) {
	RTCPInstance* instance = (RTCPInstance*)e;
	if (instance == NULL) return;

	instance->schedule(nextTime);
}

extern "C" void Reschedule(double nextTime, event e) {
	RTCPInstance* instance = (RTCPInstance*)e;
	if (instance == NULL) return;

	instance->reschedule(nextTime);
}

extern "C" void SendRTCPReport(event e) {
	RTCPInstance* instance = (RTCPInstance*)e;
	if (instance == NULL) return;

	instance->sendReport();
}

extern "C" void SendBYEPacket(event e) {
	RTCPInstance* instance = (RTCPInstance*)e;
	if (instance == NULL) return;

	instance->sendBYE();
}

extern "C" int TypeOfEvent(event e) {
	RTCPInstance* instance = (RTCPInstance*)e;
	if (instance == NULL) return EVENT_UNKNOWN;

	return instance->typeOfEvent();
}

extern "C" int SentPacketSize(event e) {
	RTCPInstance* instance = (RTCPInstance*)e;
	if (instance == NULL) return 0;

	return instance->sentPacketSize();
}

extern "C" int PacketType(packet p) {
	RTCPInstance* instance = (RTCPInstance*)p;
	if (instance == NULL) return PACKET_UNKNOWN_TYPE;

	return instance->packetType();
}

extern "C" int ReceivedPacketSize(packet p) {
	RTCPInstance* instance = (RTCPInstance*)p;
	if (instance == NULL) return 0;

	return instance->receivedPacketSize();
}

extern "C" int NewMember(packet p) {
	RTCPInstance* instance = (RTCPInstance*)p;
	if (instance == NULL) return 0;

	return instance->checkNewSSRC();
}

extern "C" int NewSender(packet /*p*/) {
	return 0; // we don't yet recognize senders other than ourselves #####
}

extern "C" void AddMember(packet /*p*/) {
	// Do nothing; all of the real work was done when NewMember() was called
}

extern "C" void AddSender(packet /*p*/) {
	// we don't yet recognize senders other than ourselves #####
}

extern "C" void RemoveMember(packet p) {
	RTCPInstance* instance = (RTCPInstance*)p;
	if (instance == NULL) return;

	instance->removeLastReceivedSSRC();
}

extern "C" void RemoveSender(packet /*p*/) {
	// we don't yet recognize senders other than ourselves #####
}

extern "C" double drand30() {
	unsigned tmp = our_random()&0x3FFFFFFF; // a random 30-bit integer
	return tmp/(double)(1024*1024*1024);
}
